Abstract
BACKGROUND: Resistance to immune checkpoint inhibitors (ICIs) represents a major unmet medical need in non-small cell lung cancer (NSCLC) patients. Vascular endothelial growth factor (VEGF) inhibition may reverse a suppressive microenvironment and recover sensitivity to subsequent ICIs. METHODS: This phase Ib/IIa, single-arm study, comprised dose-finding (Part A) and expansion (Part B) cohorts. Patients with ICIs-refractory NSCLC were enrolled to receive anlotinib (a multi-target tyrosine kinase inhibitor) orally (from days 1 to 14 in a 21-day cycle) and nivolumab (360 mg every 3 weeks, intravenously) on a 21-day treatment cycle. The first 21-day treatment cycle was a safety observation period (phase Ib) followed by a phase II expansion cohort. The primary objectives were recommended phase 2 dose (RP2D, part A), safety (part B), and objective response rate (ORR, part B), respectively. RESULTS: Between November 2020 and March 2022, 34 patients were screened, and 21 eligible patients were enrolled (6 patients in Part A). The RP2D of anlotinib is 12 mg/day orally (14 days on and 7 days off) and nivolumab (360 mg every 3 weeks). Adverse events (AEs) of any cause and treatment-related AEs (TRAEs) were reported in all treated patients. Two patients (9.5%) experienced grade 3 TRAE. No grade 4 or higher AEs were observed. Serious AEs were reported in 4 patients. Six patients experienced anlotinib interruption and 4 patients experienced nivolumab interruption due to TRAEs. ORR and disease control rate (DCR) was 19.0% and 76.2%, respectively. Median PFS and OS were 7.4 months (95% CI, 4.3-NE) and 15.2 months (95% CI, 12.1-NE), respectively. CONCLUSION: Our study suggests that anlotinib combined with nivolumab shows manageable safety and promising efficacy signals. Further studies are warranted. TRIAL REGISTRATION: NCT04507906 August 11, 2020.